Stone guard for combines

ABSTRACT

A plurality of adjacent fingers form a door which extends foreand-aft between the lower edge of the crop inlet opening in a combine body and the front edge of the concave. The door is composed of three individual sections, each of which is mounted on a transverse pivot adjacent the crop inlet opening and adapted to swing downwardly when a rock or like object is introduced between one of the sections of fingers and the threshing cylinder, thereby allowing such objects to fall away before entering the area between the cylinder and concave. A spring acting through a toggle-type linkage urges each of the finger sections upwardly against an adjustable stop, the linkage being so arranged that the urging force transmitted to the sections diminishes rapidly as the sections swing downwardly. The shape of the fingers is such that an entering rock will trip the mechanism a substantial distance forwardly of the leading edge of the concave.

D United States Patent [151 3,643,666

Denlson 51 Feb. 22, 1972 [54] STONE GUARD FOR COMBINES PrimaryExaminer-Russell R. Kinsey Assistant Examiner-J. A. Olifi' m]Attorney-4i. Vincent Harsha, Harold M. Knoth, William A. [73] Assignee:Deere 82 Company, Moline, ll]. Murray and John M. Nolan [22] Filed: Jan.30, 1970 [57] ABSTRACT [2!] 7'00: A plurality of adjacent fingers form adoor which extends foreand-aft between the lower edge of the crop inletopening in a 52 us. Cl. "130m .lT combine y and the from edge 0f theconcave The door is [Sl] Int. Cl. ..A0ll 12/20 composed of threeindividual i n each f whi h is 581 Field 0! search ..130/21.9 n, 21 JTmounted on a transverse pivot adjacent the p inlet p g and adapted toswing downwardly when a rock or like object is [56] Rglg Cit dintroduced between one of the sections of fingers and the threshingcylinder, thereby allowing such objects to fall away UNITED STATESPATENTS before entering the area between the cylinder and concave. Aspring acting through a toggle-type linkage urges each of the 2 n f;finger sections upwardly against an adjustable stop, the link- 59 ""942lac/27 age being so arranged that the urging force transmitted to the57'541 8/1866 Mend I 30/27 sections diminishes rapidly as the sectionsswing downwardly. The shape of the fingers is such that an entering rockwill trip FOREIGN PATENTS 0 ppu 'n s the mechanism a substantialdistance forwardly of the leading edge of the concave. 81,087 9/1956Denmark [30/27 IT 15 Claims, 4 Drawing Figures PATENTEUFEB22 m2 SHEET 1BF 2 INVENTOR. H. HOYT DENISON PAIENTEDFEB 22 I972 SHEEI 2 BF 2INVENTOR. H. HOYT DENISON STONE GUARD FOR COMBINES BACKGROUND OF THE INVENTION The present invention relates generally to harvesting machines ofthe type having a cylinder and concave threshing mechanism, and moreparticularly to a device for preventing rocks and like objects fromentering between the cylinder and concave.

The threshing mechanism of a conventional combine includes a largerotating threshing cylinder and an adjacent, stationary concave whichcooperate to thresh the grain from the crop passing therebetween. Thecrop is delivered rearwardly to the threshing mechanism from a forwardharvesting platform or header, which, in rocky areas, will occasionallypick up a rock along with the crop. Unless the rock is removed be foreit enters between the cylinder and concave, extensive damage to theseelements may result.

Various devices have been proposed to eliminate this problem. Forexample, a trough is commonly provided forwardly of the concave toreceive such rocks before they can be introduced between the cylinderand concave. Although this device has generally performedsatisfactorily, it has the disadvantage of requiring that the operatorperiodically stop the combine and remove the rocks which have collectedin the trough. Another common device, of which U.S. Pat. Nos. 2,8l2,766to Goffnett issued Nov. 12, I957 and 2,959,l 75 to Oberholtz et al.issued Nov. 8, 1960 are illustrative, utilizes a door forwardly of theconcave which is adapted to swing downwardly when a rock is introducedbetween the plate and the cylinder, thereby allowing the rock to passbeneath the concave. Again, however, the operator must stop the combineand reset the platform every time it is tripped.

An improved modification of this latter device is disclosed in US. Pat.No. 2,305,159 to Heckman et al. issued Dec. 15, I942. The Heckman devicealso utilizes a door yieldably mounted forwardly of the concave, thoughit further includes a spring mechanism which automatically returns thedoor to its operating position after a rock has been discharged,Although this feature obviates the need for the operator to periodicallyreset the mechanism, certain other features of the Heckman device renderit not entirely satisfactory for use with today's high-capacitycombines. For example, the shape of the door utilized in Heckman is suchthat an entering rock will not trip the mechanism until almost to theleading edge of the concave. At this point, the momentum of the rock inthe direction of the concave, imparted by the high rotational speed ofthe cylinder, is of such magnitude that instead of falling through theopening, the rock will instead strike the concave. This problem isaggavated by the fact that, in the Heckman design, the spring forcemaintaining the door in its normal position increases as the door isopened downwardly. Thus, although a rock may hit the door withsuflicient force to partially open it against the urging of the spring,the force may not be sufficient to open the door wide enough to allowthe rock to pass. An additional feature of the Heckman device, theprovision ofa single door extending the entire width of the cylinder, issomewhat undesirable in that an excessive amount of unthreshed grain isallowed to fall through the relatively large opening created when thedevice is tripped.

SUMMARY OF THE INVENTION It is, accordingly, a primary object of thepresent invention to provide an improved stone guard for a cylinder andconcave. It is a further object to provide such a device which is simpleand reliable in operation.

The invention consists, generally, of a transverse pivot adjacent thecrop inlet opening and forwardly of the leading edge of the concave, adoor swingable about the pivot normally extending to the edge of theconcave, and a spring acting through a toggle-type linkage urging thedoor upwardly against the stop defining its normal position. The door isprovided with a hump between its forc-and-aft edges such that the radialclearance between the cylinder and the door is least at a pointsubstantially forwardly of the leading edge of the concave. Thus, astone entering with the crop will first come in contact with the door atthis point rather than at a point adjacent the edge of the concave, andwill fall downwardly through the open space created when the door isswung downwardly before its rearward momentum carries it into theconcave. Additionally, the toggle linkage is so designed that the forceurging the door toward its normal position diminishes rapidly as thedoor is swung downwardly. Thus, a rock having sufficient momentum toinitially trip the mechanism will open the door sufi'tciently to allowthe rock to pass. The door consists of a plurality of independentlyswingable sections, which results in greater operating sensitivity thanwould be the case if a single continuous door were utilized. When onesection is tripped, the others remain in place, thus reducing both theamount of unthreshed grain lost through the opening and the returnmomentum of the door. In addition. each section is formed of a pluralityof spaced rods or fingers, such that the grain separated from the cropin the area of the door can fall between adjacent fingers.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described inconjunction with the accompanying drawings in which:

FIG. 1 is a partial side view of a combine, with portions broken away tomore clearly illustrate the invention,

FIG. 2 is a view similar to FIG. 1, showing one of the door sections inits tripped position.

FIG. 3 is an enlarged rear view of the invention, the middle sectionbeing shown along the line 33 of FIG. I.

FIG. 4 is an enlarged view taken along the line 4-4 of HGV 3, with thefolded position of the door shown in phantom.

DESCRIPTION OF THE PREFERRED EMBODIMENT The threshing system of aconventional combine, illustrated partially in FIG. 1, includes atransverse threshing cylinder 10 mounted on a shaft 12 for rotationalmovement in the direction indicated by the arrow, the shaft 12 beingjournalcd at its respective ends in sidewalls l4 and [6 of the combinethreshing house 18. A plurality of rasp bar elements 20. spacedcircumferentially about the cylinder 10, cooperate with the gratemembers 22 on a stationary concave 24 mounted below the cylinder I0 tothresh the grain from the crop passing therebetween. As is well known inthe art, the concave 24 is adjustably mounted relative to the cylinderl0, whereby the clearance therebetween can be varied to best suit theparticular crop being threshed. A conventional cropgathering device orheader mounted fonvardly on the com bine (not shown) severs the cropfrom the field as the machine advances therealong and feeds it centrallyto a feeder house, shown partially at 26, which extends rcarwardly tothe thrush ing house I8. Contained within the feeder house 26 is acontinuous, flight-type conveyor 28 which moves the crop rearwardly to adischarge point forwardly of the concave 24.

When operating under rocky soil conditions, the forward gathering devicewill occasionally pick up a rock which will be conveyed rearwardly withthe crop to the threshing mechanism. According to the present invention,a stone guard, indicated generally by the numeral 30, is mounted betweenthe discharge end of the conveyor 28 and the leading edge of the concave24 to remove such rocks from the crop before it is introduced betweenthe cylinder and conca e. As shown in FIG. 3, the stone guard 30comprises three identical sections 32 which conjunctively span theentire width of the threshing house I8 between the walls 14 and I6, thesections 32 being independently operable as will hereinafter appear.Although three sections are shown, the stone guard could consist of anynumber of units.

Each section 32 has a separate grate or door 34 extending fore-and-aftbetween the discharge end of the conveyor 28 and the leading edge of theconcave 24. The door 34 consists of a plurality of transversely spaced,bent rods or fingers 3h commonly joined at their forward ends, as bywelding, to a transverse pivot member 38. The rods 36 are additionallyconnected by a transverse bar 40 welded to the undersides of the rodsrearwardly of the member 38. The ends of the pivot member 38arejoumaled, respectively, in aligned apertures in left and right sidemembers 42 and 44V The members 42 and 44 are held in rigid transverserelation by means of a transverse plate 46 secured at its respectivesides to the transverse legs of the members 42 and 44 with bolts orsimilar fastening means 48. As shown in FIG, 3, the center section ofthe rock guard 30 is secured to the two outer sections by means of bolts50 interconnecting the fore-and-aft legs of adjacent side members 42 and44, and the outer sections are, in turn, secured to the combinethreshing house 18 by means of bolts 52 interconnecting the foreand-aftlegs of the side members 42 and 44 with the respective sidewalls l4 and16. It is thus seen that the three sections 32 form a rigid transverseunit spanning the walls l4 and [6.

A toggle-type linkage, indicated generally at 54, connects each of thedoors 34 with its respective transverse plate 46. The linkage comprisesa pair of brackets 56 welded to pposite sides of and extendingdownwardly from the center rod 36, a pair of upper arms 58 pivotallymounted at their upper ends on a pin 60 received in the brackets 56, apair of brackets 62 fixed to the rear surface of the plate 46, a pair oflower arms 64 pivotally mounted at their lower ends on a pin 66 receivedin the brackets 62, and a pin 68 pivotally connecting the upper andlower ends of the respective arms 64 and 58. A helical spring 70, actingbetween the pin 68 and a lug 72 welded to the rear surface of the plate46, urges the arms 58 and 64 into alignment, which, in turn, urges thedoor 34 up wardly about the pivot member 38. Such movement of the door34 is limited, however, by a pair of transversely spaced flexible cablesor stop means 74 acting between the plate 46 and the door. A loop formedin the upper end of each of the cables 74 is received in an aperture inthe bar 40, and a similar loop in the lower end of the cables isreceived in the eye of a threaded stud 76. The stud 76 is adjustablyheld in the plate 46 by means of cooperatively threaded nuts 78 oneither side of the plate. The normal position of the door 34 can thus bevaried by appropriate adjustment of the stud 76.

It will be apparent from FIG. 4 that the toggle linkage 54 is soconstructed that arms 58 and 64 move increasingly off center as the doorpivots downwardly to its rock-ejecting position. Although the length ofthe spring 70 and thus the force exerted between the lug 72 and the pin68 increases as the door pivots, the geometry of the linkage is suchthat the effec tive urging force transmitted to the door concurrentlydecreases.

As shown in H05. 1 and 2, the door 34 is so shaped that when the rockguard 30 is in its normal operating position, the point of minimumradial clearance between the door 34 and the cylinder is located asubstantial distance forwardly of the leading edge of the concave 24,substantially midway between the fore-and-aft ends of the door. Thisminimum clearance, adjustable as previously noted by means of nuts 78 onthe stud 76, deten'riines the minimum size rock that will be ejected bythe mechanism In operation, a rock introduced with the crop. such asthat designated R in FIG. 2, will be wedged between the cylinder 10 andthe door 34 at the point ofleast clearance or, depend ing on its size,at a point forwardly thereof. The door will thus be forced to pivotdownwardly. creating a gap forwardly of the concave, and the downwardmomentum ofthc rock will carry it therethrough. Although the rock R isgiven a substantial rearward momentum by the cylinder 10 tending tocarry it into the edge of the concave, the distance between the concavcand the point at which the mechanism is initially tripped is such thatthe downward momentum of the rock will carry it through the gap beforeit can strike the concave.

As shown in FIG. 4, the downward movement of the door 34 is limited bythe bar 40 contacting the arms SH After the rock is ejected, the spring70 rcturns the door to H5 o eriiiing position against the stop means 74.Only one section 32 is normally tripped by a single rock; the other twosections remain in their operating positions, thereby minimizing theloss of unthreshed grain through the gap and the return momentum of thedoor.

lclaim:

l. in a crop harvesting machine having a transverse threshing cylinder,a concave supported on the machine adjacent the lower portion of thecylinder for cooperation therewith, and crop conveyor means mountedforwardly on the machine for moving the crop rearwardly to the cylinderand concave, said conveyor means having a discharge end spaced forwardlyfrom the concave, the improvement residing in means to prevent rocks andlike objects from entering between the cylinder and concave, said meanscomprising: a stationary support on the machine; transverse pivot meanscarried by the support adjacent the discharge end of the conveyor; transverse door means mounted on the pivot means for swinging movementbetween a normal operating position wherein the door means extendsfore-andaft between the pivot means and the concave, and a rock-ejectingposition wherein the door means is swung downwardly about said pivotmeans from said normal operating position; means acting between thesupport and the door means for exerting a decreasing upward biasingforce on the door means as the latter is swung downwardly from itsnormal operating position to its rock-ejecting position; and stop meansacting between the support and the door means to limit the upwardmovement of the door means to its normal operating position 2. In a cropharvesting machine having a transverse threshing cylinder, a concavesupported on the machine adjacent the lower portion of the cylinder forcooperation therewith, and crop conveyor means mounted forwardly on themachine for moving the crop rearwardly to the cylinder and concave. saidconveyor means having a discharge end spaced forwardly from the concave,the improvement residing in means to prevent rocks and like objects fromentering bctwccn the cylinder and concave, said means comprising. astationary support on the machine, transverse pivot means carried by thesupport adjacent the discharge end of the conveyor; trans verse doormeans mounted on the pivot means for swinging movement between a normaloperating position wherein the door means extends forc-and-aft betweenthe pivot means and the concave, and a rock-ejecting position whereinthe door means is swung downwardly about said pivot means from saidnormal operating position, said door means having a point of minimumradial clearance with the threshing cylinder substantially midwaybetween its fore-and-aft ends when in its normal operating position;means acting between the support and the door mean for biasing thelatter upwardly about said pivot means, said biasing means includingmeans for exerting a decreasing upward biasing force on the door meansas the latter is swung downwardly form its normal operating position toits rocloejecting position and stop means acting between the support andthe door means to limit the upward movement of the door means to itsnormal operating position.

3. The invention described in claim I wherein said means for exerting adecreasing upward biasing force comprises toggle linkage means havingfirst arm means pivotally mounted on the door means, second arm meanspivotally mounted on the support, and means pivotally connecting saidfirst and second arm means; and said biasing means further includesspring means acting between said toggle linkage means and the support,

4. The invention described in claim 1 wherein and door means comprises aplurality of individual transverse SCClttilts, each section beingindependently swingablc about the trans verse pivot means and each beingindependently httbL'tl up wardly about said pivot means by said biasingmeansv 5. The invention described in claim I wherein the door meansComprises a plurality of transversely spaced, fort-and aft extending rodmembers.

6 The invention described in claim I wherein the stop means comprisesflexible element means 7. The invention described in claim 6 wherein theflexible element means comprises cable means.

8. The invention described in claim I wherein the stop means includesadjustment means for varying the normal operating position of the doormeans.

9. In a crop harvesting machine having a transverse threshing cylinder,a concave supported on the machine adjacent the lower portion of thecylinder for cooperation therewith, and crop conveyor means mountedforwardly on the machine for moving the crop rearwardly to the cylinderand concave, said conveyor means having a discharge end spaced forwardlyfrom the concave, the improvement residing in means to prevent rocks andlike objects from entering between the cylinder and concave, said meanscomprising: a stationary support on the machine, transverse pivot meanscarried by the support adjacent the discharge end of the conveyor;transverse door means mounted on the pivot means for swinging movementbetween a normal operating position wherein the door means extendsfore-and-aft between the pivot means and the concave, and arock-ejecting position wherein the door means is swung downwardly aboutsaid pivot means from said normal operating position; means actingbetween the support and the door means for biasing the latter upwardlyabout said pivot means, said biasing means exerting a decreasing biasingforce on the door means as the latter is swung downwardly from itsnormal operating position to its rock-ejecting position; and stop meansacting between the support and the door means to limit the upwardmovement of the door means to its normal operating position.

10. The invention described in claim 9 wherein the stop means includesadjustment means for varying the normal operating position of the doormeans.

1 l. The invention described in claim 10 wherein said means exerting adecreasing biasing force comprises toggle linkage means having first armmeans pivotally mounted on the door means. second am! means pivotallymounted on the support. and means pivotally connecting said first andsecond arm means; and said biasing means further includes spring meansacting between said toggle linkage means and the supportv 12. Theinvention defined in claim 10 wherein said door means has a point ofminimum radial clearance with the threshing cylinder intermediate itsfore and aft ends when in its normal operating position.

13. The invention defined in claim 10 wherein said door means has apoint of minimum radial clearance with the threshing cylindersubstantially midway between its fore-andaft ends when in its normaloperating position.

14. The invention defined in claim 10 wherein said door means comprisesa plurality of individual transverse sections, each section beingindependently swingable about the transverse pivot means and each beingindependently biased upwardly about said pivot means by said biasingmeans.

15 The invention defined in claim 10 wherein the door means comprises aplurality of transversely spaced, foreandaft extending rod members.

i i i l UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION patent3,643,666 Dated 22 February 1972 Inventor(s) Henry Hoyt Denison It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 4, line 53, change "form" to from lines 57, 65, 70, and 73,change "1" to 2 Column 5, line 3, change "1" to 2 Column 6, lines 5, l2,16, 20, and 25, change "10" to 9 Signed and sealed this 27th day of June1972.

(SEAL) Attest:

EDNARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM PO-105D (1 USCOMM-IJC 60376-P69 U.S, GOVERNMENT PRINTINGOFFiCE' 9'9 D3l*334

1. In a crop harvesting machine having a transverse threshing cylinder, a concave supported on the machine adjacent the lower portion of the cylinder for cooperation therewith, and crop conveyor means mounted forwardly on the machine for moving the crop rearwardly to the cylinder and concave, said conveyor means having a discharge end spaced forwardly from the concave, the improvement residing in means to prevent rocks and like objects from entering between the cylinder and concave, said means comprising: a stationary support on the machine; transverse pivot means carried by the support adjacent the discharge end of the conveyor; transverse door means mounted on the pivot means for swinging movement between a normal operating position wherein the door means extends fore-and-aft between the pivot means and the concave, and a rock-ejecting position wherein the door means is swung downwardly about said pivot means from said normal operating position; means acting between the support and the door means for exerting a decreasing upward biasing force on the door means as the latter is swung downwardly from its normal operating position to its rock-ejecting position; and stop means acting between the support and the door means to limit the upward movement of the door means to its normal operating position.
 2. In a crop harvesting machine having a transverse threshing cylinder, a concave supported on the machine adjacent the lower portion of the cylinder for cooperation therewith, and crop conveyor means mounted forwardly on the machine for moving the crop rearwardly to the cylinder and concave, said conveyor means having a discharge end spaced forwardly from the concave, the improvement residing in means to prevent rocks and like objects from enteRing between the cylinder and concave, said means comprising: a stationary support on the machine; transverse pivot means carried by the support adjacent the discharge end of the conveyor; transverse door means mounted on the pivot means for swinging movement between a normal operating position wherein the door means extends fore-and-aft between the pivot means and the concave, and a rock-ejecting position wherein the door means is swung downwardly about said pivot means from said normal operating position, said door means having a point of minimum radial clearance with the threshing cylinder substantially midway between its fore-and-aft ends when in its normal operating position; means acting between the support and the door mean for biasing the latter upwardly about said pivot means, said biasing means including means for exerting a decreasing upward biasing force on the door means as the latter is swung downwardly form its normal operating position to its rock-ejecting position and stop means acting between the support and the door means to limit the upward movement of the door means to its normal operating position.
 3. The invention described in claim 1 wherein said means for exerting a decreasing upward biasing force comprises toggle linkage means having first arm means pivotally mounted on the door means, second arm means pivotally mounted on the support, and means pivotally connecting said first and second arm means; and said biasing means further includes spring means acting between said toggle linkage means and the support.
 4. The invention described in claim 1 wherein said door means comprises a plurality of individual transverse sections, each section being independently swingable about the transverse pivot means and each being independently biased upwardly about said pivot means by said biasing means.
 5. The invention described in claim 1 wherein the door means comprises a plurality of transversely spaced, fore-and-aft extending rod members.
 6. The invention described in claim 1 wherein the stop means comprises flexible element means.
 7. The invention described in claim 6 wherein the flexible element means comprises cable means.
 8. The invention described in claim 1 wherein the stop means includes adjustment means for varying the normal operating position of the door means.
 9. In a crop harvesting machine having a transverse threshing cylinder, a concave supported on the machine adjacent the lower portion of the cylinder for cooperation therewith, and crop conveyor means mounted forwardly on the machine for moving the crop rearwardly to the cylinder and concave, said conveyor means having a discharge end spaced forwardly from the concave, the improvement residing in means to prevent rocks and like objects from entering between the cylinder and concave, said means comprising: a stationary support on the machine; transverse pivot means carried by the support adjacent the discharge end of the conveyor; transverse door means mounted on the pivot means for swinging movement between a normal operating position wherein the door means extends fore-and-aft between the pivot means and the concave, and a rock-ejecting position wherein the door means is swung downwardly about said pivot means from said normal operating position; means acting between the support and the door means for biasing the latter upwardly about said pivot means, said biasing means exerting a decreasing biasing force on the door means as the latter is swung downwardly from its normal operating position to its rock-ejecting position; and stop means acting between the support and the door means to limit the upward movement of the door means to its normal operating position.
 10. The invention described in claim 9 wherein the stop means includes adjustment means for varying the normal operating position of the door means.
 11. The invention described in claim 10 wherein said means exerting a decreasing biasing force comprises toggle linkage means having first arm means pivotally moUnted on the door means, second arm means pivotally mounted on the support, and means pivotally connecting said first and second arm means; and said biasing means further includes spring means acting between said toggle linkage means and the support.
 12. The invention defined in claim 10 wherein said door means has a point of minimum radial clearance with the threshing cylinder intermediate its fore and aft ends when in its normal operating position.
 13. The invention defined in claim 10 wherein said door means has a point of minimum radial clearance with the threshing cylinder substantially midway between its fore-and-aft ends when in its normal operating position.
 14. The invention defined in claim 10 wherein said door means comprises a plurality of individual transverse sections, each section being independently swingable about the transverse pivot means and each being independently biased upwardly about said pivot means by said biasing means.
 15. The invention defined in claim 10 wherein the door means comprises a plurality of transversely spaced, fore-and-aft extending rod members. 